Traffix Group director Will de Waard said the company did not require the traffic forecasting qualifications.

The consultants used by the Victorian government to help sell the controversial East West Link are not qualified to provide traffic forecasts.

The report relied on by the Coalition government to claim commuters could save up to an hour in travel each day have been thrown into question by revelations that consultants Traffix Group are not accredited by VicRoads to provide the forecasts.

A spokesperson for Premier Denis Napthine claimed that the research was a “travel time survey, not traffic modelling”.

“They are two completely different things,” spokesman James Copsey said.

The clarification of the Traffix study comes despite Dr Napthine’s press release on August 6 claiming that the “independent study, conducted by leading traffic engineering and transport modelling consultant Traffix Group…illustrates the need to get on with building the East West Link as soon as possible”.

The controversy follows Fairfax Media revelations that the government had tried to bury another report prepared by consulting firm Veitch Lister for the Linking Melbourne Authority last July which showed that motorists faced more, rather than less, congestion.

The $8 billion project, which links Melbourne’s Eastern Freeway with the Western Ring Road, is shaping up as the key political flashpoint in the lead-up to November’s hotly contested state election. Traffic forecasts for major road infrastructure have been put under increased scrutiny after a $46 million class action was launched in May against consultants Arup over allegedly misleading traffic forecasts for the company that managed Brisbane’s Airport Link toll roads, which went into receivership last year.

In order to be registered under the VicRoads scheme, consultants must demonstrate they have the relevant “skills and knowledge to conduct strategic and macro level transport modelling, which includes the ability to model current and future transport demand”, the VicRoads registry states.

Traffix Group director Will de Waard said the company did not require the traffic forecasting qualifications because they had relied on data by engineering firm GHD, as well as AusTraffic, who are also not registered for traffic forecasting.

“It should be noted this was not a traffic modelling task and as our report clearly states all modelling referred to is documented in the GHD, October 2013 report.”

Traffix said that its principal consultant, Henry Turnbull, who also sits on Planning Panels Victoria, had no involvement in the process or in preparing the report.

“And consequently has not created any conflict in the matter,” Mr de Waard said.

One industry insider said that “the consultants had been engaged to dress up previous government work as an independent verification of the government’s claims”.

VicRoads confirmed that “prequalification is generally a prerequisite for companies undertaking traffic modelling for VicRoads”.

Last year VicRoad’s manager of network modelling and analysis, Douglas Harley, quit after warning the road authority’s strategy and planning head, David Shelton that traffic figures being used to justify the project could not be trusted.

Opposition Leader Daniel Andrews has blasted the report as being beset by “dodgy traffic modelling” and he doubted anything about the project “stacks up”.

Shadow treasurer Tim Pallas said that if elected the Labor government would honour the East West Link stage one contracts.

Mr Pallas said the project would proceed not because they had a legal obligation to, as contracts would be signed before the November 29 election, but because Victorians needed to understand that “when the state of Victoria says they’re going to do something, they do”.